1. Field of the Invention
The present invention relates to a vapor phase growth method of forming a film in a process of manufacturing a semiconductor device, and more specifically to a method of manufacturing a semiconductor light emitting element including a group III-V compound film containing nitrogen as a group V element.
2. Description of the Related Art
In recent years, with the development of high-speed and high-density data process systems, there has been a growing demand for laser devices which can generate beams having short wavelengths. In order to achieve miniaturization, lightness of weight, and power-saving, it is essential to produce a short-wavelength laser from a semiconductor device. It is preferable to use a nitride-based mixed crystal made of GaAlInN as the material of a short-wavelength-light emitting element, since it can be controlled to form a band gap of a range as broad as from 2.2 to 6.0 eV. Further, it is preferable to use SiN to form the final passivation film and the gate insulating film of the semiconductor device, since SiN has superior dielectric and diffusion barrier characteristics. When SiN is used to form the passivation film, growing it at a low temperature is especially important. Ammonia is used as a raw material for producing nitrogen to be contained in the nitride layer. It is desirable to grow a layer containing nitrogen at as low a temperature as possible, since growing the layer at high temperature will cause nitrogen to evaporate from the crystal. However, an ammonia molecule has three equivalent H--N bonds and is stable, with the result that the decomposition temperature is very high, and thus a considerable great amount of ammonia is required for growing the film at low temperature.
As should be clear from the above, the use of ammonia to grow a short-wavelength-light emitting element and the passivation film of a semiconductor device is disadvantageous in that a great amount of ammonia is required to achieve low temperature growth of the films by preventing evaporation of nitrogen from the crystal.